1. Field of the invention
This invention relates to a waterproof connector, and more particularly to the construction of mounting a rubber plug (waterproof packing) between a terminal and an electric wire.
2. Related Art
In order to impart an enhanced waterproof ability to an electric connector, it is necessary to use a housing of a liquid-tight construction, and it is also necessary to provide a liquid-tight construction between the housing and the wire having a terminal attached thereto, the terminal being adapted to be inserted into and fixed to a housing. Therefore, it is a common practice to provide a waterproof packing, through which an electric wire extends, at a portion of connection between the wire and the terminal.
As a conventional waterproof terminal, there is known a construction (cf. Unexamined Japanese Utility Model Publication Nos. 62-26871 and 63-18779) shown in FIGS. 6 and 7, in which a hollow cylindrical waterproof packing 4 of an elastic material, such as rubber or a synthetic resin, is fitted on an insulation 2 of an electric wire 1 from which part of conductors are exposed, and clamp pawls 7 of a metal terminal 6 are compressively clamped to a tubular portion 5 of the packing 4, and further an insulation barrel 8 is press-connected to the conductors 3, thereby connecting the metal terminal 6 and the wire 1 together.
In the above construction, the terminal need to be press-connected by the clamp pawls 7 in such a manner that a cut end surface 2a of the insulation lies flush with an end surface 5a of the tubular portion, or the end surface 5a of the tubular portion lies slightly rearwardly of the end surface 2a of the insulation.
Namely, it is necessary that the insulation and the packing, as well as the packing and the terminal, should be compressively connected together in such a manner that the two are properly positioned with respect to each other. If the compressive connection is done without such proper positioning (for example, if the compressive clamping is done in such a manner that the insulation is extended to the insulation barrel to overlap part of this barrel), this invites an imperfect conduction. If the clamp pawls are disposed so rearwardly that the packing and the insulation are compressively clamped by these clamp pawls in such a manner that the clamp pawls overlap the end of the packing and the insulation, the packing is broken, and the packing is withdrawn rearwardly because of an insufficient compressive clamping force applied by the clamp pawls. For these reasons, it has been necessary to effect the terminal clamping operation in such a manner that the packing, the terminal and the wire are accurately held in their respective proper positions.
However, to effect the clamping operation with the above three parts thus held in their respective proper positions has required much time and labor, and has been extremely poor in the efficiency of the operation.